Video library system using recorded index information and stored library data

ABSTRACT

A video library system for an apparatus using a video tape accumulates index information regarding the video tape and includes a memory storing the library data, a microcomputer, an on screen display circuit and a pair of adders. Index information is added via the first adder to the vertical blanking interval of the composite video signal under the control of the microcomputer and the library data is built and stored in the memory with library data corresponding to the index information. The microcomputer also permits the library data to be output to a monitor via on screen display circuit and the second adder.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus with a video indexfunction such as video cassette recorders (VCRs) and camcorders using avideo tape, and more particularly to a video library system whereinindex information is recorded on a control track of a tape and isdetected during the vertical blanking period of a video signal whilerecording or reproducing the video signal with respect to video tape tothereby allow a portion desired by a user to be searched with a simpleoperation of function keys. A method for improved searching is alsodisclosed.

2. Description of the Prior Art

In order to find a video signal of a desired portion among recordedcontents on a video tape, a video index search system (VISS) and a videoaddress search system (VASS) are employed in apparatuses such as VCRsand camcorders using the video tape. A classification label may beattached on the video tape. The VISS is utilized to facilitate thesearch of recorded contents on the video tape during playing thereof bystoring a specific index signal on a control track of the video tape inadvance at the start point of recording. The VASS facilitates the searchof recorded contents on the video tape during playing thereof by storinga specific index address on the control track of the video tape inadvance at the start point of recording. The specific addresscorresponds to a point of the video tape at which the recording begins,and value of the specific address differs according to the recordingpoint.

However, the adoption of the VISS or VASS has the following problems insearching the recorded contents on the video tape.

With VISS, since each index signal recorded on every recording point isthe same throughout the video tape, the video tape must be played fromits beginning to the end when searching for the desired contents. WithVASS, a fixed address can be utilized when the exact position of thedesired content from the start point of the search is already perceived.When the position of the desired content is not definite, the searchmust be performed from the start point of the search to the end of thevideo tape or must be performed after rewinding the video tape. If adesired picture is not then displayed, unsearched portions must besearched. Consequently, all contents recorded on the video tape shouldbe searched.

To search the recorded contents on the video tape, the present inventionemploys a video library system (hereinafter referred to as "VLS") whichdoes not adopt VISS or VASS and does not require labelling on the videotape. The VLS stores information data on the video tape to inform theuser of information data about the video tape. In other words, when onevideo tape among several tapes is inserted into a set (e.g., VCR),information indicating the order of the inserted tape among the tapesand information registered by the user during recording are inserted toinform the user of the location of the recorded content. Then, theinformation about the video tape is recorded or played, using a remotecontroller or key board installed on the set.

A technique for recording and playing message data in a verticalblanking period is disclosed by U.S. Pat. No. 5,097,348. However, thistechnique utilizes only a superimposition function.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide a videolibrary system for recording or playing an index (ID) code indicatinginformation about the video tape during vertical blanking period of avideo signal to enable a user to search a desired picture without usingthe VISS or VASS. A method for embodying the video library system isalso provided.

To achieve the above object of the present invention, there is provideda video library system capable of searching content desired by a user byrecording index information in a composite video signal loaded on avideo tape during a vertical blanking period and reproducing therecorded index information. A sync signal separator separates a verticalsync signal and a horizontal sync signal from the composite videosignal. A microcomputer counts the horizontal sync signal separated bymeans of the sync signal separator to determine the vertical blankingperiod including the index information recorded therein, and outputs theindex information to be recorded in the vertical blanking period of thecomposite video signal as well as outputs data for displaying the indexinformation on a screen and a plurality of control signals forperforming a search operation. Memory means stores a librarycorresponding to the index information processed in the microcomputer toinput and output the library. Then, an index separator separates anddecodes the index information loaded in the vertical blanking period,which is supplied from the microcomputer, and outputs the decoded signalto the microcomputer. A motor drives the video tape to search the indexinformation recorded on the video tape in response to the control signalfrom the microcomputer, and an adder adds the index information from themicrocomputer to the composite video signal from a plurality of videosignal input sources to output the result of addition. An on-screendisplay finally combines the index information and library from themicrocomputer with the composite video signal from the adder to outputthe result of the combination.

To achieve another object of the present invention, there is provided amethod for embodying a video library system for recording andreproducing index information formed of a tape index code and an indexcode and stored in a vertical blanking period of a video signal, andselecting a desired video signal by confirming a library correspondingto the index information by a user, including the steps of:

checking the insertion of a new video tape;

detecting the vertical blanking period from the video signal when thevideo tape is newly inserted;

checking the existence of the index code in a vertical blanking signalof the vertical blanking period when vertical blanking period isdetected, and reading out the library corresponding to the index codefrom the microcomputer;

checking the start of recording when the video tape is not newlyinserted, and checking a mode whether it is of a recording or not afterincreasing the index code when the start of recording is confirmed;

checking the insertion of a new video tape when the mode is of therecording, and outputting the index code for displaying on a screenafter increasing the tape index code when the video tape is the new one;

displaying the library on the screen during performing theabove-described steps in all case that the vertical blanking period isnot detected, the mode is not of the recording regardless of inserting aused video tape, and the library corresponding to the index code isalready read out by the microcomputer; and

searching the video signal corresponding to the received index code,after confirming the content of the library displayed on the screen.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and other advantages of the present invention willbecome more apparent by describing in detail a preferred embodimentthereof with reference to the attached drawings in which:

FIG. 1 is a block diagram showing a video library system according tothe present invention;

FIG. 2 is a flow chart performing a method for embodying the videolibrary system according to the present invention;

FIGS. 3A to 3E are flow charts for showing the subroutine andsupplemental steps of the method according to FIG. 2;

FIG. 4 illustrates states displayed on a screen during a libraryoperation; and

FIGS. 5A and 5B are waveforms showing horizontal and vertical syncsignals, respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a composite video signal is received from anunshown external video signal source, i.e., a video signal input lineand a tuner, via an adder 80. A microcomputer 90 is connected to a syncsignal separator 20 for separating a horizontal sync signal H-sync and avertical sync signal V-sync from the composite video signal. One side ofthe microcomputer 90 is connected to an index separator unit consistingof a data slicer 30 and a decoder 40.

The microcomputer 90 counts the horizontal sync signal H-sync andvertical sync signal V-sync. By this counting operation, a verticalblanking period which includes ID information of a tape ID codedesignating the tape number and an ID code designating a start point ofthe recording is determined, so that the microcomputer 90 outputs avertical blanking signal V-BLK of the vertical blanking period which hasthe ID information, thereby controlling the reproduction of the IDinformation.

When the vertical blanking signal V-BLK determined as above is outputfrom the microcomputer 90 to the data slicer 30, ID information storedduring the recording is separated in the data slicer 30 from thecomposite video signal which is received from the adder 80 to the dataslicer 30 by means of the vertical blanking signal V-BLK. The decoder 40is connected to the data slicer 30 to decode the separated IDinformation into a signal recognizable by the microcomputer 90.

The microcomputer 90 is also connected to a memory 50 for storing alibrary corresponding to the ID code which increases one by one perrecording, a motor 55 driven by a control voltage and a control signalF/R from the microcomputer 90, and a key board 10 incorporated with keysfor controlling the microcomputer 90 such as a search key, a clear key,a library on/off key, character keys. An amplifier is connected to themicrocomputer 90 for amplifying an unshown remotely-controlled signal.

The microcomputer 90 is further connected to an on-screen display (OSD)60 for displaying the ID code and library corresponding to the ID codeextracted from the memory 50 in response to the input by the key board10. The OSD 60 is connected to a mixer 70 which combines the compositevideo signal from the adder 80 with an on-screen display signal from theOSD 60 to thus output the result of the combination. A white or colorsignal for controlling color of a character displayed on a screen isreceived from one side of the mixer 70.

Therefore, the microcomputer 90 extracts the library corresponding tothe ID code from the memory 50 to output the extracted library to theOSD 60. The on-screen display signal from the OSD 60 is supplied to themixer 70 to be combined with the composite video signal from the videosignal source to display the ID information on the screen. At this time,the white or color signal input to the mixer 70 controls the color ofthe displayed portion on the screen, which technique is well known and,thus, is not discussed further. The ID information displayed via the OSD60 is illustrated in FIG. 4, which will be explained later in thedescription with reference to FIGS. 2 and 3.

The user may play, clear or change the ID code by selecting a desiredlibrary, using various functional keys on the key board 10 such as thesearch key, clear key, character keys and library on/off key.

Meanwhile, in case of a new tape which has no information thereon, theID code on the tape cannot be extracted from the memory 50 when the IDcode is intended to be recorded on the video tape. This is due to thefact that the memory 50 has no ID code in case of the new tape. However,the microcomputer 90 automatically outputs a tape ID code from its IDcode output terminal IDo, and the tape ID code is combined with theexternal composite video signal (e.g., a television broadcasting signal)in the adder 80 and can be recorded. The tape ID code is also stored inthe memory 50. At this time, the tape ID code and ID code are recordedin a format of 0001 as shown in FIG. 4. When the tape is not a new one,an ID code is extracted to the microcomputer 90 since the ID code isstored in the memory 50, the extracted ID code is increased by one, andthe tape ID code is left unchanged. Thus, the increased ID code iscombined with the external composite video signal to be recorded, andthe increased ID code is also recorded on the memory 50. The reason ofincreasing the ID code by one is in that the ID code is increased uponrecording whereas the tape ID code is increased in case of a new tape.

According to the present invention as described above, the tape ID codeand ID code being index information are recorded or reproduced in thevertical blanking period of the video signal, thereby enabling thesearch of the library of the video tape without adopting VISS or VASSfunctions.

The operation of the apparatus having the above-stated construction willbe described in detail with reference to FIGS. 2 and 3A to 3E.

FIG. 2 is a flow chart for performing a method embodying the videolibrary system according to the present invention. Here, in accordancewith the insertion of a video tape, an ID code or a librarycorresponding thereto is displayed on the screen, or the ID code iscombined with the external composite video signal being recorded.

In step 100, the microcomputer 90 determines whether a video tape isnewly inserted or not. In step 200, when the video tape is newlyinserted, the microcomputer 90 mutes a video signal output andautomatically performs a short play to check whether a vertical blankingperiod having the ID code exists or not. If the vertical blanking periodexists in step 200, in step 300, the ID code separated from thecomposite video signal by means of the vertical blanking signal from themicrocomputer 90 is decoded in the decoder 40 to be input to themicrocomputer 90 which in turn confirms the existence of the ID code inthe signal received from the decoder 40. If there is no ID code, thetape is regarded as a new one, so that a new flag is set to one.Contrarily, if there is an ID code, the tape is regarded as a used one,so that the new flag is set to zero and then the content of the librarycorresponding to the ID code input from the decoder 40 to themicrocomputer 90 is read out from the memory 50.

On the other hand, when the video tape is not newly inserted one in step100, step 400 is performed. In step 400, if the recording is started,the ID code is increased by one, and the mode is checked whether it isof a recording or not. When it is determined that the mode is therecording mode in step 400, in step 500, the new flag is checked whetherit is set to one. If the new flag is set to one, the tape ID code isincreased by one indicating that the tape being a new one. Whereas, ifthe new flag is not set to one, which means that the tape is not a newone, the tape ID code is not increased and the ID code is output fromthe microcomputer 90 to the mixer 70 for the on-screen display.

If the vertical blanking period does not exist in step 200, the mode isnot the recording mode, or the step 300 is carried out, an on-screendisplay subroutine (hereinafter referred to as SUB1) is called fordisplaying the library corresponding to the ID code according to thekey-input, in step 600. After performing step 600, a current ID code andan ID code selected by the user are compared with each other inaccordance with the input of the search key, and the motor 55 iscontrolled in response to the result of the comparison. Thus, in step700, a first search subroutine (hereinafter referred to as SUB2) iscalled for playing.

FIGS. 3A to 3E are flow charts for showing the subroutine andsupplemental steps of the method according to FIG. 2.

FIG. 3A is a flow chart of the SUB1 of step 600 shown in FIG. 2. In step610, the input key is checked to determine whether it is a library keyfor showing the ID information or not. Here, when the input key isdetermined as the library key, in step 620, the library-on state (i.e.,the on-screen display of the library) is confirmed. Thereafter, the OSD60 is cleared to turn off the library in case of the library-on state,or the content of the library of the currently loaded tape is displayedon the screen.

When the library-key input is not identified in step 610, in step 630,the library-on state is confirmed. In case of the library-on state, anarrow-key input is checked. When the input key is determined as thearrow key in step 630, in step 640, a cursor on the OSD displaying thetitle of the program corresponding to the ID code shown in FIG. 4 ismoved towards a direction in conformity with the arrow key.

Meantime, if the input key is not the arrow key in step 630, the inputkey is checked to determine whether it is a character key or not in step650. If the character-key input is confirmed, a corresponding characteris output by means of the cursor in step 660. If the character key isnot input in step 650, in step 670, a clear-key input is confirmed, sothat the portion currently indicated by the cursor on the correspondingline is cleared. After performing the above-described steps, the SUB2shown in FIG. 2 is carried out.

FIG. 3B is a flow chart showing the SUB2 of step 700. After performingthe SUB1 of step 600, as shown in FIG. 3A, SUB2 is called in step 700.Therefore, by the input of the search key, the current ID code and theID code selected by the user are compared with each other to control thedrive of the motor 55, thereby executing the play operation.

In more detail, when step 710 determines that the input key is thesearch key for searching a desired program under on-screen displaystate, in step 720, the library-on state is confirmed. Then, in case ofthe library-on state, the current ID code is compared with the ID codeselected by the user by means of the search key. Thus, when they are thesame, the tape is played.

If the current ID code and the ID code selected by the user to besearched are not the same during step 720, a distance, i.e., timedifference from the recording time of a program recorded on the currentID code to the recording time of a program recorded on the selected IDcode, is calculated in step 730. In step 740, the time difference iscompared with a predetermined value, so that the tape is fully loadedwhen the time difference is smaller than the predetermined value, or isunloaded when it is greater than the predetermined value. Referring toFIG. 4, assuming that the current ID code is 0001 having a PROGRAM-1recorded thereon, and the selected ID code by the search key is 0003having a PROGRAM-3 recorded thereon, the time difference from thecurrent ID code to the ID code to be searched is two hours because thePROGRAM-1 is one hour long by 10:00 to 11:00, and the PROGRAM-2 whose IDcode 0002 is one hour long by 8:00 to 9:00. Accordingly, the timedifference from the ID code 0001 having the PROGRAM-1 to the ID code0003 having the PROGRAM-3 is two hours, so that the ID code is no needto be read out for about one hour and fifty minutes. Due to this reason,the tape is forwarded an amount corresponding to one hour and fiftyminutes in the unloading state in order to prevent the tape and tapehead from being damaged and to minimize the time loss caused byforwarding the tape under the full-loading state for a long time. Inother words, the selected program is searched by forwarding the tapeunder the full-loading state in case of little time difference from theprogram corresponding to the current ID code to the programcorresponding to the selected ID code. But, if the time difference isgreat, the tape-travel is performed under the unloading state and thenchanged to be the full loading state to search for the desired program.Consequently, the predetermined value acts as a reference fordetermining which tape status can be used to search the desired programmore quickly and safely, e.g., between the full-loading and unloadingstates.

After performing step 740, the size of the current ID code is comparedwith that of the selected ID code. The smaller current ID code than theselected ID code means that the position of the selected ID codeprecedes the current ID code. Thus, the motor 55 is rotated to wind thetape forwards until reaching the portion to be searched. Meantime, thelarger or equal current ID code than the selected ID code means that theselected ID code is disposed after the current ID code, and thus themotor 55 is rotated to rewind the tape backwards until reaching theportion to be searched.

If step 710 determines that the input key is not the search key, asecond search subroutine (hereinafter referred to as SUB3) is called instep 760 to check the existence of the sync signal for performing anoperation according to the result of step 710.

FIG. 3C is a flow chart showing the SUB3 of FIG. 3B. The existence ofthe sync signal is checked in step 761. When the sync signal is notdetected, it is determined whether the current ID code is the final codeor not in step 762. Here, the non-existence of the sync signal denotesthat nothing is displayed on the screen. The result of step 762indicates that the current ID code is the final ID code, the tape isrewound, otherwise a high-speed search is performed in step 764.Meanwhile, if the sync signal exists in step 761, the search isperformed for determining the existence of the ID code behind thecurrent position of the tape in step 765. Therefore, when the ID codeexists, in step 766, the recorded content is reproduced and the searchis finished.

In addition to the sequential operation described heretofore withreference to FIGS. 2 and 3A to 3C, an abruptly occurring horizontal orvertical interrupt can be processed as illustrated in FIGS. 3D and 3E,respectively, which will be explained in view of FIGS. 5A and 5B.

First, as shown in FIG. 3D, the interrupt with respect to the verticalsync signal V-sync is processed as below. In step 801, the interrupt ischecked to determined whether it occurs at the start point of thevertical sync signal or not. When a point indicated by VPI of FIG. 5B isdetermined as the start point of the vertical sync signal in step 801,the horizontal sync signal is set to zero to inhibit further counting ofthe horizontal sync signal since the vertical blanking period mayinclude the ID code. When interrupt does not occur at the start point ofthe vertical sync signal in step 801, the interrupt is checked todetermine again whether it occurs at the end point of the vertical syncsignal, i.e., a point indicated by VPO in FIG. 5B, in step 803. When thepoint is determined as the end of the vertical sync signal, there is noneed to count the horizontal sync signal due to the fact that the videosignal follows the end of the vertical sync signal. Accordingly, thehorizontal sync signal is set to zero to inhibit further counting of thehorizontal sync signal, and then the operation being performed beforethe occurrence of the interrupt is continued.

On the other hand, the interrupt with respect to the horizontal syncsignal is processed as below. In step 811, the interrupt is checked todetermine whether it occurs at the start point of the horizontal syncsignal designated by HPI in FIG. 5A or not. Thus, when the interruptoccurs at the start point of the horizontal sync signal, the horizontalsync signal is increased by one so as to search a portion having the IDcode in step 812. In step 813, the interrupt is checked to determinewhether it occurs during the vertical sync signal period correspondingto a section A in FIG. 5A. When the vertical sync period is confirmed instep 813, in step 814, the counted value of the horizontal sync signalis compared with a predetermined value in order to confirm the countedvalue of the horizontal sync signal to be included in the verticalblanking period having the ID code. When the counted value is greaterthan or equal to the predetermined value, the vertical blanking erasingsignal is output to the data slicer 30, in step 815. If not, in step816, the vertical blanking signal is not output to the data slicer 30but the operation being performed before the occurrence of the interruptis continued.

According to the present invention as described above, the horizontaland vertical sync signals are separated from the composite video signal,and the microcomputer 90 counts the sync signals to output the verticalblanking signal loading the ID code to the data slicer 30 duringrecording, so that the data slicer 30 separates the ID code from thecomposite video signal to output the separated ID code to the decoder40. Following this operation, the decoder 40 decodes and outputs the IDcode as a signal recognizable by the microcomputer 90 which in turnextracts a library corresponding to the ID code recorded during therecording from the memory 50 and then outputs the extracted library tothe OSD 60. The on-screen display signal from the OSD 60 is combinedwith the composite video signal from the adder 80 in the mixer 70 andthe result of the combination is output to be reproduced on the screen.The tape ID code and ID code displayed on the screen by means of theon-screen display signal are selected, cleared or stored again by meansof various functional keys on the key board 10.

On the other hand, during recording, the microcomputer 90 extracts theID code stored in the memory 50 to increase the ID code by one, and theresult is output to the adder 80 to be combined with the externallyinput composite video signal and recorded. Therefore, the ID informationincluding tape ID code and ID code can be recorded or played during thevertical blanking period.

As a result, by recording and playing the tape ID information of tape IDcode and ID code in the vertical blanking period, the video librarysystem can be embodied without adopting VISS, VASS or labels.

While the present invention has been particularly shown and describedwith reference to particular embodiments thereof, it will be understoodby those skilled in the art that various changes in form and details maybe effected herein without departing from the spirit and scope of theinvention as defined by the appended claims.

What is claimed is:
 1. A video library system for searching contentdesired by a user recording index information in a composite videosignal recorded on a video tape during a vertical blanking period andfor reproducing the recorded index information, comprising:a sync signalseparator for separating a vertical sync signal and a horizontal syncsignal from said composite video signal; a microcomputer for determiningsaid vertical blanking period including said recorded index informationrecorded therein with respect to said horizontal sync signal, forproviding the index information to be recorded during said verticalblanking period of said composite video signal, for generating datapermitting display of said recorded index information on a screen, andfor producing a plurality of control signals permitting a searchoperation to be performed; a memory for storing library datacorresponding to said recorded index information processed in saidmicrocomputer; an index separator for separating and decoding saidrecorded index information recorded during said vertical blanking periodand supplied from said microcomputer, and providing a decoded signal tosaid microcomputer; a motor for driving said video tape for searchingsaid recorded index information recorded on said video tape in responseto said control signals from said microcomputer; an adder for addingsaid index information from said microcomputer to a received compositevideo signal; and means for combining said recorded index informationand said library data from said microcomputer with said composite videosignal from said adder so as to permit display of a combined signal. 2.The video library system as claimed in claim 1, wherein said indexinformation comprises a tape index signal for classifying said videotape and an index signal for identifying recorded content.
 3. The videolibrary system as claimed in claim 1, wherein said index separatorcomprises:a data slicer for separating said recorded index informationin said vertical blanking period from said composite video signalreceived from said adder; and a decoder for decoding said recorded indexinformation separated in said data slicer to produce said decoded signalrecognizable by said microcomputer.
 4. The video library as claimed inclaim 1, wherein said means comprises:an on-screen display forconverting said recorded index information and said library data fromsaid microcomputer into an on-screen display signal; and a mixerreceiving said display signal for mixing said composite video signalfrom said adder with said display signal.
 5. A video library systempermitting a search for a desired program by a user, wherein indexinformation is recorded during a vertical blanking period of a compositevideo signal recorded on a video tape, by reproducing the recorded indexinformation, said system including a sync signal separator generating avertical sync signal and a horizontal sync signal from the compositevideo signal, an on-screen display circuit superimposing data on thecomposite video signal to produce a combined composite video signal anda motor driving said video tape during a search for said recorded indexinformation on said video tape, said video library system comprising:afirst adder including first and second input terminals and a firstoutput terminal, wherein a selected one of said first and said secondinput terminals receives said composite video signal; a second adderincluding third and fourth input terminals and a second output terminal,wherein said first output terminal is serially connected to a selectedone of said third and fourth input terminals; a memory storing librarydata corresponding to said index information; a microcomputeroperatively coupled to a non-selected one of said first and second inputterminals so as to permit addition of said index information to saidcomposite video signal, operatively coupled to said first outputterminal of said first adder so as to permit recovery of said recordedindex information, and operatively coupled to a non-selected one of saidthird and fourth input terminals, wherein said microcomputer receivessaid recorded index information recovered from said video taperesponsive to said horizontal sync signal, wherein said microcomputerroutes at least one of said recorded index information and said librarydata to said non-selected one of said third and fourth input terminalsso as to permit said second adder to produce said combined compositevideo signal, and wherein said microcomputer generates a plurality ofcontrol signals supplied to said motor for performing said search. 6.The video library system as claimed in claim 5, wherein said indexinformation comprises a tape index signal for classifying said videotape and an index signal for identifying recorded content of eachrespective video tape.
 7. The video library system as claimed in claim5, further comprising an index separator operatively coupled betweensaid first output terminal and said microcomputer and providing decodedindex information to said microcomputer.
 8. The video library system asclaimed in claim 7, wherein said index separator comprises:a data slicerfor separating said recorded index information inserted during saidvertical blanking period from said composite video signal received fromsaid first output terminal; and a decoder for decoding said recordedindex information separated in said data slicer to produce a decodedsignal supplied to a microcomputer input terminal corresponding to saiddecoded index information.
 9. The video library system as claimed inclaim 5, wherein said further comprises a on-screen display circuitserially connected between said microcomputer and said non-selected oneof said third and fourth input terminals,wherein said display circuitconverts said recorded index information and said library data receivedfrom said microcomputer into an on-screen display signal, and whereinsaid composite video signal and said on-screen display signal arecombined to produce the combined composite video signal.
 10. The videolibrary system as claimed in claim 5, wherein said system furthercomprises a key board operatively connected to said microcomputerproviding key data to said microcomputer so as to permit saidmicrocomputer to compare said library data with said recorded indexinformation during said search.